1. Field of the Invention
The present invention relates to a method of forming color images and, more particularly, to a method of forming color images by causing differences in light-scattering and transparent optical states.
2. Description of the Related Art
Images have previously been displayed in various forms such as, for instance, outputs displayed on a cathode ray tube (CRT) or a display monitor using a twisted nematic (TN) liquid crystal from a television or video tape recorder, or from a computer performing a dialogue operation. Generally, however, high-resolution images such as documents or figures produced by a word processor (WP) or facsimile equipment are displayed on paper as printed hard copies.
Recently, polymer liquid crystal displays for outputting still images have been proposed in, e.g., Japanese Patent Laid-Open No. 10930/1984. The use of polymer liquid crystals has the following advantages: it is possible to form a thin film, and obtain a large display area; it is easy to compose elements of a flat display with a polymer liquid crystal; and it is possible to obtain memory images which are as clear and stable as paper outputs. Another advantage is that the optical characteristics of a polymer liquid crystal can be reversibly changed and varied by the application of heat or an electric field so an image can be repeatedly displayed and erased. It is, of course, particularly advantageous to use the polymer liquid crystal in a poly-domain state in order to obtain a display image which is only minimally dependent on the visual field angle.
Various proposals have been made concerning the formation of color images using an image forming medium having one or more polymer liquid crystals. For instance, the present applicant has previously proposed combining a polymer liquid crystal image forming medium with a color filter (Japanese Patent Laid-Open No. 154120/1989); and adding colored materials to the polymer liquid crystal(s), arranging portions of the colored liquid crystal(s) as picture elements on a surface of the medium, and selecting colors for display (Japanese Patent Laid-Open No. 576/1990).
However, when color images are displayed with the above-described media utilizing the light scattering of the polymer liquid crystals, the scattering angle and the scattering efficiency both vary depending on the wavelength of the scattered light. Thus, although displays exhibit excellent image resolution, their tone is unacceptable.
For this reason, there is demand for a method capable of easily correcting the color balance of a display image which is applicable to an image forming medium employing polymer liquid crystal(s).